Document Type
Dissertation
Date of Award
5-31-2024
Degree Name
Doctor of Philosophy in Civil Engineering - (Ph.D.)
Department
Civil and Environmental Engineering
First Advisor
Jay N. Meegoda
Second Advisor
Taha F. Marhaba
Third Advisor
Wen Zhang
Fourth Advisor
David Washington
Fifth Advisor
Cristiano L. Dias
Sixth Advisor
Lucia Rodriguez-Freire
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a group of stable synthetic chemicals that are highly persistent and harmful pollutants to the environment and human health. PFAS have caused a strong public and regulatory response due to their ubiquitous presence in the environment and toxicity to humans. The application of ultrasound is one of the most effective treatment technologies for the mineralization of PFAS in contaminated water. However, this technology is treated as a black box causing the inability to be optimized. Therefore, there is a pressing need to investigate the intricate dynamics of PFAS degradation under ultrasound to unlock its full potential for environmental remediation.
To address this knowledge gap, Molecular Dynamics simulations have been used to reveal the molecular interactions driving the PFAS degradation. The simulations will help to elucidate the mechanisms governing PFAS bond-breaking and subsequent mineralization by subjecting the PFAS molecules to elevated temperatures, mimicking the conditions of bubble collapse induced by ultrasound. Furthermore, the study investigates the adsorption behavior of PFAS molecules onto bubble surfaces, highlighting the adsorption mechanism of PFAS compounds into the bubbles. These explorations deepen the understanding on the impact of hydrophobicity into the PFAS mineralization mechanism. In addition, the study explores the complex behavior of PFAS molecules under pyrolytic conditions following bubble implosion. Factors such as functional head groups and chain length will be systematically studied to reveal their influence on PFAS degradation kinetics and pathways. Moreover, the investigation extends to diverse environmental contexts, water, oxygen, nitrogen, and air. The simulation of PFAS degradation across a diverse spectrum of environmental configuration will reveal the optimal parameters for maximizing PFAS mineralization.
Ultimately, the research goal is to comprehensively model the intricate interplay between imploded cavitational bubbles and PFAS molecules, offering invaluable insights into the fundamental mechanisms around PFAS degradation and guiding the optimization of ultrasound-based remediation strategies. The results will not only serve to validate experimental fmdings but also bridge the gap between empirical observations and theoretical predictions, providing a robust foundation for designing effective PFAS remediation protocols. Thus, this holistic approach promises to advance our understanding of PFAS remediation processes and accelerate progress towards mitigating the harmful threat posed by these persistent pollutants.
Recommended Citation
Bezerra de Souza, Bruno, "A molecular dynamics study on the destruction mechanism of per and polyfluoroalkyl substances due to ultrasound technology" (2024). Dissertations. 1827.
https://digitalcommons.njit.edu/dissertations/1827
Included in
Civil Engineering Commons, Computational Chemistry Commons, Environmental Chemistry Commons, Environmental Engineering Commons, Environmental Sciences Commons
